When can I plant Zinnia in Zone 3a

One of the first steps we take when we are estimating our gardening schedule is find our USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for our area.

It's a good idea to estimate when it's a good idea to plant zinnia by looking at the USDA zone info for Zone 3a.


Planting Calendar for Zinnia

Frost tolerance for zinnia: Not tolerant of frost.
When you should plant them: After the last frost.

You really shouldn't plant zinnia until after the last frost when the weather gets warmer because they do not do well in cold weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant zinnia
Possibly ok, but a risky time to plant zinnia
Probably not a good time to plant zinnia

The earliest that you can plant zinnia in Zone 3a is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant zinnia and expect a good harvest is probably August. Any later than that and your zinnia may not have a chance to fully mature. You can get started a few weeks earlier by starting your zinnia indoors.

Last Frost Date

The average date of last frost is May 15 in Zone 3a. In the coldest months of winter we can expect an average low temperature of -40°F.

It's important to remember that our actual date of last frost is just an average because it is based on the USDA zone info for Zone 3a and it can change quite a bit from year to year. Half of the time in Zone 3a last frost occurs after May 15 so always be ready to protect your zinnia if we have a late frost.

USDA Zone Info for Zone 3a

Here is the info for USDA Zone 3a.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-40°F
Highest Expected Low-35°F

This means that on a really cold year, the coldest it will get is -40°F. On most years you should be prepared to experience lows near -35°F.

Plants to Grow in Zone 3a

You may be interested in our other planting guides for Zone 3a.